A utility knife is described in DE 37 36 968 [U.S. Pat. No. 4,899,443] in which a guide member is received in a grip sleeve and carries a blade support such that it can be displaced between a safety position and a cutting position. A spring fastened to the guide member and to the blade support biases the blade support into the safety position. The blade is held in a seat between two plates of the blade support that can be moved to one another. The abutment of the plates against inner walls of the grip sleeve prevents the plates from being separated from each other and the blade from being removed from the seat. A blade change can be performed by pulling the guide member backward out of the grip sleeve with the blade support. The plates of the blade support can then be separated from one another, and the used blade can be replaced.